In the conventional art, for example, among disc players for compact discs used to reproduce music and the like, there are known to be disc players that reduce the number of motors by using a drive switching mechanism to selectively drive a loading mechanism and pick-up moving mechanism using a single motor, as is disclosed, for example, in Japanese Laid-Open Patent Publication No. 2000-298903.
This disc player is provided with an idler plate, which is rotatable about the axis of a drive gear that is rotated by drive force from a motor and which functions as a drive switching mechanism. The idler plate is rotated to a disc loading position for transmitting drive force to the loading mechanism or to a pick-up moving position for transmitting drive force to the pick-up moving mechanism in accordance with the rotation direction of the drive gear by means of the friction generated between the drive gear and an idler gear provided on the idler plate. This switches the transmission of the drive force from the idler gear to one or another of the loading mechanism or the pick-up moving mechanism.
In disc players of this structure, a problem of operational instability occurs because a neutral point is generated in the transmission of the drive force at which the drive force of the drive gear is not transferred from the idler gear to both the loading mechanism and the pick-up moving mechanism during the rotation of the idler plate. When the drive transmission is switched by moving the idler gear between the loading mechanism and the pick-up moving mechanism, the operation is prevented from becoming unstable by moving the idler gear so as to engage an intermediate member arranged between the loading mechanism and the pick-up moving mechanism.
Therefore, in a conventional disc player structure, a problem of operational instability occurs because a neutral point is generated in the drive force transmission at which the drive force of the drive gear is not transferred from the idler gear to both the loading mechanism and the pick-up moving mechanism during the rotation of the idler plate, and it becomes necessary to use a special intermediate member to solve the problem. This leads to further problems of increasing the number of parts and making the structure more complex.
Further problems of increasing structural complexity and increasing size arise due to the need for a special locking means for locking the idler plate at each position when it is rotated to the disc loading position or the pick-up moving position, in order to allow the loading mechanism or pick-up moving mechanism to operate freely, and to allow forward and reverse rotation of the motor.
It is an object of the present invention to provide a disc drive device capable of reliably transmitting and switching drive force from a single motor to a loading mechanism and a pick-up moving mechanism.